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OCR for page 29
Atomic, Molecular, and
Optical Physics in the
United States Today
This chapter summarizes the demographics of atomic, molecular,
and optical (AMO) physics and outlines some of its contributions to the
community of science and to the nation. The concluding section
discusses the changing role of the United States in AMO research.
DEMOGRAPHICS OF ATOMIC, MOLECULAR, AND OPTICAL
PHYSICS
The most comprehensive recent study of AMO physics in the United
States is the Survey by the Committee on Atomic and Molecular
Science (CAMS).* We briefly summarize here the major points.
Size of the Field
Based on 2264 returned questionnaires (from an initial mailing of
6000), the Survey estimates that the community of professional scien-
tists actively working in atomic and molecular science in the United
States is approximately 3000.
*Subcommittee on Atomic and Molecular Survey, NRC Committee on Atomic and
Molecular Science, Survey of Atomic and Molecular Science in the United States,
1980-1981, National Academy Press, Washington, D.C., 1982.
29
OCR for page 30
30 ATOMIC, MOLECULAR, AND OPTICAL PHYSICS
Employment
Academic institutions
Industrial or corporate research
Federally funded research and development centers
Government laboratories (civilian or military)
Not-for-profit research organizations
Distribution of Effort
52%
18%
15%
11%
4%
Within broad categories, the research effort is distributed as follows:
Structural properties of atoms and molecules
Atomic and molecular collisional interactions
Interactions with radiation
Techniques and instrumentation
Interfaces with other areas of science and technology
The breakdown between experimental and theoretical work is
Primarily experimental
Experimental and theoretical
Primarily theoretical
19%
25%
25%
12%
19%
54%
20%
36%
THE EDUCATIONAL ROLE OF ATOMIC, MOLECULAR, AND
OPTICAL PHYSICS
AMO physics plays an active role in educating scientists in the
United States at both the undergraduate and graduate levels. Because
the field is one of a small number in physics that permit experimental
research in a college setting, AMO physicists are frequently sought for
teaching positions in colleges. AMO physics often plays a prominent
role in undergraduate education in universities because its laboratories
are generally located on campus and the research lends itself to
participation by students. By providing research opportunities for
undergraduate students in colleges and universities, AMO research
plays an effective role in attracting capable students to science.
The major educational role of AMO physics, however, is in the
training of professional physicists who are qualified to pursue many
OCR for page 31
AMO PHYSICS IN THE UNITED STATES TODA Y 31
different careers in science. AMO research is generally carried out in
small groups; it is not unusual for a student to execute an entire
experiment single-handedly under the direction of a supervisor
constructing the apparatus, taking and analyzing the data, and working
out the theory. The research requires experimental skills including
mechanical design and construction, high-vacuum techniques, elec-
tronics, lasers, electron and optical spectroscopy, charged and neutral
particle beams, and computers. Often a student working in AMO
physics becomes expert in several of these areas. Furthermore, in
AMO physics it is possible for a single person to work actively both in
theory and in experiment, providing an unusually versatile capability.
These skills are invaluable for careers ranging from basic physics and
chemistry to applied science and engineering.
AMO physicists are in demand for positions in national laboratories
and in industry. In national laboratories, for instance, a continued
supply of AMO physicists is essential for the development of lasers for
applications such as underwater communication, isotope separation,
satellite tracking, and defense systems. AMO physicists are deeply
involved in fusion research and in environmental monitoring programs.
AMO physicists are needed by industry in areas of advanced technol-
ogy such as fiber-optics communications, laser manufacturing, com-
bustion analysis, optical data processing, photochemistry, and materi-
als preparation.
SCIENTIFIC INTERFACES AND APPLICATIONS
AMO physics contributes broadly to neighboring fields of physics
and to other areas of science. Some of the contributions take the form
of devices and techniques—the panoply of lasers, light-scattering
spectroscopy, supersonic molecular-beam methods, clusters, surface-
scattering spectroscopy, and spin-polarized quantum fluids, to name a
few. Others are at the deepest scientific level, as for instance in
astrophysics (see Chapter 7, section on Astrophysics) or at the
interface between nuclear and atomic phenomena (see Chapter 7,
section on Nuclear Physics). In addition, AMO physics provides
atomic and molecular data, which are essential to fields such as plasma
physics and atmospheric science.
AMO physics contributes directly to national needs through a host of
applications: plasma diagnostics based on AMO physics are essential
to our fusion program; fiber-optics systems play a growing role in
civilian and military communications; remote sensing is being increas-
ingly employed for monitoring the environment and industrial pro-
OCR for page 32
ATOMIC. Mf)LECIJI.AR Awn f,PT~f:Ar P~rYcrrc
FIGURE 2.1 Remote Sensing Using Lasers. With lasers it is now possible to detect
minute traces of chemicals from a distance. In environmental and energy programs the
new techniques can be used to detect pollutants in the atmosphere sensitively and
rapidly, to study aerosols and smog, to measure turbulence and wind velocity, and to
monitor the stratospheric ozone layer. The techniques can also be employed to study
combustion in a furnace or in engines while they operate. The illustration shows a
blown-up three-dimensional map of the concentration of ethylene glycol that has leaked
to the atmosphere from an oil refinery in Germany. The map is superimposed on an aerial
photograph of the refinery. (The long arrows illustrate the points on the ground that
correspond to the corners of the map.) The gas leak was mapped with a laser 0.5
kilometer away from the plant. The sensitivity of the measurement is 20 parts in 109. The
peaks in the map reveal two sources of escaping gas. The gas is not coming from the two
smokestacks that can be seen in the photo, however; the sources were pinpointed to be
two leaks in separate buildings. (Photo courtesy of Max-Planck-Institute for Quantum
Optics, Garching, Federal Republic of Germany.)
cesses such as combustion (see Figure 2.11; and laser processing is
expected to have a revolutionary impact on manufacturing. AMO
physics is vital to innumerable military applications including naviga-
tion, communication, and laser-based defense systems; it has contrib-
uted to medical care through laser surgery and nuclear magnetic
resonance body imaging.
Chapters 7 and 8 describe the scientific interfaces and applications of
OCR for page 33
AMO PHYSICS IN THE UNITED STATES TODAY 33
AMO research. The activities are broad, and the chapters are by no
means comprehensive. Nevertheless, they provide evidence of the
many contributions of AMO research to science and to society.
THE ECONOMIC IMPACT OF ATOMIC, MOLECULAR, AND
OPTICAL PHYSICS
Over a long period- and sometimes quickly basic science repays
the investment. The return from AMO physics is often large and
sometimes rapid. Assessing the full economic impact of AMO physics
would be a formidable task, but a few representative examples can help
to indicate the magnitude of the return. Nuclear magnetic resonance,
whose origins trace back to molecular-beam magnetic resonance, has
been applied to a new type of body imaging for medical diagnosis (see
Chapter 8, section on Medical Physics). Although the technique is still
in its infancy, more than 20 companies are already developing magnetic
resonance imaging machines, and hospitals have started to install the
devices. The projected sales by 1990 are estimated to be $2 billion to $3
billion. The economic impact of magnetic resonance body imaging is
far greater than this, however, for it comes not so much from the sales
as from the benefits of improved medical diagnosis: high productivity,
better health care, and a better quality of life.
The major economic return from AMO physics in the past decade
came from the laser and the developments of modern optics. The
conception, development, and reduction to practice of the laser and
other modern optical techniques provides a striking illustration of the
confluence of academic and industrial research and development in
AMO physics. In 1982, the total commercial sales for lasers, laser
equipment, and services were $1.5 billion. The laser is having a
revolutionary impact on some industries; the fiber-optic industry
illustrates how rapidly a new technology can grow. It was not until the
mid-1970s, when low-loss fibers were first developed, that commercial
applications became a realistic possibility. In 1981 the sales were $24
million; by 1983 they were $620 million. Annual sales in fiber optics in
1990 are projected to be $1.4 billion. The total sales of laser printing
equipment through 1988 are projected to be between $5 billion and $10
billion.
The role of lasers and modern optics in industrial applications such
as robotics, laser manufacturing, and photochemical processing can be
expected to strengthen the nation's economy for years to come. (See
Figure 2.2. The use of lasers in manufacturing is described in Chapter
8 in the section on Materials Processing.) These industries are vital to
OCR for page 34
34 ATOMIC, MOLECULAR, AND OPTICAL PHYSICS
FIGURE 2.2 Laser-Assisted Manufacturing. Industry is finding more and more uses
for lasers, and with the robotics revolution laser-assisted manufacturing promises to
become a major industrial force. Laser light is particularly well suited to robotics
because the energy can be directed and controlled by computer with unmatched speed
and accuracy. Manufacturing processes in which lasers are used include cutting, drilling,
welding, surface hardening, and specialized applications such as machining gemstones,
ceramics, and semiconductors. Material from the most delicate foil to steel plate O.S-inch
thick can be machined. The upper photograph shows a heavy-duty laser machining
installation that cuts, drills, and welds parts in a wide range of geometries. At lower left
is an internal gear that was processed by a laser drill. At lower right, the container for a
cardiac pacemaker made of titanium is shown being welded by a pulsed laser welder.
Further discussion is in Chapter 8 in the section on Manufacturing with Lasers. (Photos
courtesy of Lasers and Applications.)
OCR for page 35
AMO PHYSICS IN THE UNITED STATES TODAY 35
the national interest if the United States is to compete successfully with
other nations in these times of rapid technological development.
One study of the patterns of future employment in the United States*
indicates that by 1990 there will be 200,000 new jobs in the United
States in industries related to fiber-optics communications. The use of
lasers in manufacturing will generate even more employment: it is
predicted that by 1990 the number of these new jobs will be 600,000.
In assessing the economic role of AMO physics, the origin of the
laser is worth recalling. The progenitor of the laser was the ammonia
beam maser, which was conceived and developed in an academic AMO
physics laboratory. Since these early beginnings AMO physics in
industrial, academic, and government institutions has made innumer-
able contributions to the development of lasers and laser-related
optical industries. The growth of these industries stands as testimony
of the economic return to society that can occur when capable
scientists in AMO physics are given the freedom and resources to
pursue their goals.
THE HEALTH OF THE FIELD IN THE UNITED STATES
Through the early 1970s, scientific leadership in AMO physics came
largely from the United States. Advances such as the invention of
magnetic resonance, the discovery of the Lamb shift, the observation
of quantum diffraction in high-resolution atomic scattering, and the
invention of the laser left no room for doubt about the strength of AMO
physics in the United States. The situation is changing. AMO physics
was enthusiastically supported in Europe during the past decade, while
in the United States it experienced a period of austerity. As a result,
the relative level of activity in Europe has advanced dramatically.
Europe is now fully competitive with the United States.
In accelerator-based atomic physics, the Europeans and Japanese
are likely soon to establish a clear technological advantage. One of the
most important new technologies, highly charged ion sources, has been
vigorously developed in Europe: the lack of support for developing
these sources in the United States makes it difficult for laboratories in
this country to pursue research in this scientifically exciting area. If
judged by the relative numbers of contributed papers at the Interna-
tional Conference on the Physics of Electronic and Atomic Collisions,
*Newsweek, Vol. 100, p. 78, Oct. 18, 1982. Based on data from the Bureau of Labor
Statistics, Forecasting International, Ltd., and Occupational Forecasting, Inc.
OCR for page 36
36 ATOMIC, MOLECULAR, AND OPTICAL PHYSICS
activity in atomic and molecular scattering in Europe has grown
conspicuously. In 1971, the breakdown was 47 percent United States
versus 36 percent Europe and United Kingdom; in 1983 it was 26
percent versus 54 percent, respectively. Both meetings were held in
Europe.
In the early 1970s, there were but a handful of groups at German
universities working in optical physics and lasers. Most of the ad-
vances in this field came from laboratories in the United States. The
rapidly rising number of German publications reveals that this is no
longer true. West Germany has assumed a forefront position. In 1974,
the Deutsche Forschungsgemeinschaft initiated a program to provide
funds for acquisition of modern laser equipment by researchers in
German universities. As a result, there were periods when major
United States laser manufacturers were shipping more than half of their
production to Germany. Most German AMO physics groups now have
several state-of-the-art laser systems. In the United States, however,
most laboratories could not afford to purchase essential equipment.
U.S. laboratories now suffer from a serious lack of lasers. Fifty percent
of AMO research involves lasers; the shortage of these devices affects
practically every area of AMO research in the United States.
There are many excellent AMO research groups in the United
States, and there are numerous opportunities for scientific advance. A
central concern, however, is that if one extrapolates the effect of the
funding pattern over the past decade into the decade to come, it
becomes evident that the quality of AMO research in the United States
will be seriously compromised. It is not essential that the United States
be preeminent in every area of AMO research, but we must remain
competitive and we must maintain excellence in areas where major
advances seem likely. We have attempted to define those areas in the
Program of Research Initiatives. To assure the continued vitality of
AMO physics in the United States it is essential to move forward
vigorously on these research initiatives.
Representative terms from entire chapter:
amo research
